1. To Determine the Ability of Sciatic Nerve Axons to Regenerate in Optic Nerve and Control Grafts. a. To compare the rates of regeneration in optic nerve and control grafts. b. To document the location of regenerating axon tips in optic nerve and control grafts using light and electron microscope autoradiography. c. To evaluate the structural relationship between regenerating axons and graft in both settings with particular attention to synapse-like associations between regenerating axons and cells in the optic nerve graft. 2. To Measure the Turnover of Actin, Tubulin, and the Neurofilament Triplet Proteins at the Axon Tip in Optic Nerve and Control Grafts. a. To determine the time-course of arrival of these proteins in the graft. b. To measure the rates at which each of these polypeptides disappears from optic nerve grafts, control grafts, and neuromas.